Various types of machines perform a repetitive function or number of events and in some instances, such as where the machine is leased, it is necessary to determine or record the number of events the machine performs. Most commonly employed recorders or monitors are mechanical counters which normally have a decimal display. These mechanical counters are normally expensive, need approximately 1/2 inch on an actuating arm to function or they require a solenoid relay to drive them. Also, they are subject both to "skimming" where the counter is by-passed and events are not recorded, and tampering, where the counter itself is tampered with to modify readings.
Thus, there exists a need for an electronic counter which does not rely on mechanical movement of any of the machine parts to record events. Further, the counter should accumulate counts internally and the counts should be displayed only when a compatible display unit is mated with the counter.